You see a white buoy with an orange crossed diamond and black lettering. what does this marker tell you?

A float or sign may demonstrate just the image or may likewise show Swim Area, Beach, Keep Out, No Boats, Closed Area, Dam, and so on. 
A precious stone shape with a cross means vessels must keep out. A float or sign may demonstrate just the image or may likewise show Swim Area, Beach, Keep Out, No Boats, Closed Area, Dam, and so on. 
A white float, or another water marker, with orange crossed precious stones, demonstrates the zone is beyond reach to all vessels. These territories could be closed off for various reasons, for example, swimming ranges, dams, and spillways. On the off chance that there is a solitary orange precious stone with dark lettering, it shows risks in the water, for example, stumps, shakes or dams. In any case, you should maintain a strategic distance from those regions.

This is true. yes. indeed.